Column-mold.



W. M. VENABLE.

COLUMN MOLD.

APPLICATION FILED AUG.29,1912.'

Patented Dec. 8, 1914.

WITNgiSES: 1 W. I k INIg/ENTOR. BY 4 7 z p it A T TORNE Y.

UNITED STATES PATENT OFFICE.

WILLIAM M. VENABLE, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO BLAW STEEL 'CONSTRUCTION COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

COLUMN-MOLD.

Specification of Letters Patent.

Patented Dec. 8, 1914.

Application filed August 29, 1912. Serial No. 717,664.

To all whom it may concern:

Be it known that I, IVILLIAM M. VnnABLn, a citizen of the United States, residlng at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Column-Molds, of which the following is a specification.

The invention relates to what may be termed column molds, although the invention is applicable to the formation of all sorts of concrete structures circular in cross section, such as tanks, chimneys, and the like, and it will be understood that the term column mold is used in its generic sense to include molds for forming all kinds of concrete structures circular in cross section. The invention has for its primary objects the provision of a circular column mold or form of great rigidity which can be cheaply constructed and which can be adjusted to the formation of columns of varying diameters; the provision of a mold having improved means whereby the vertical length of the mold may be varied; and the provision of improved means for stiffening the sheet metal plates employed in the construction and making them conform to a substantially true circular form of the desired diameter. One embodiment of the invention is shown in preferred form in the accompanying drawing, wherein- Fig. 1 is an end view of the column form, and Fig. 2 is a side elevation thereof.

As illustrated in Fig. 2, the form or mold consists of two tubular sections the lower of which extends between the points marked a and b, and the upper of which extends between the .parts marked 0 and d, but it will be understood that as many tubular sections may be employed as is necessary or convenient. The two tubular sections referred to are substantially the same in construction, and a description of one will suffice for both, after which attention will be directed to the means whereby the upper section is securely maintained in position upon the lower section, with the ends of the two sections in telescopic relation.

Referring now to the upper'section which lies between the points markedc and d, it will be noted by reference to Fig. 1 that this section is made up of four segmental plates, 1, 2, 3, and 4, the plates 1,2, and 3 being of the same width, while the plate 4 is of much less width, and constitutes What may be termed a filler plate, the purpose of which will be more fully described later. It will be noted that each of the plates 1, 2, 3, and at is provided at its vertical edges with outstanding flanges 5, the flange on one plate abutting the flange on the next plate.

Extending circumferentially of the plates 1, 2, 3, and 4 are a plurality of what may be termed stiffening bands, such bands consisting of rigid metal plates set edgewise, and serving not only to give stiffness to the form, but also to make it conform to a true circular shape. The upper section of the mold as illustrated in Fig. 2 is shown as provided with two of the these stiffening bands, but it will be understood that any desired number may be used. In the form of stiffening band as illustrated, the band is made up of four sections 6, 7, 8, and 9, (Fig. 1), but it will be understood that the number of sections may be varied to suit different conditions, depending upon the size of the mold and upon the number of flanged metal plates employed. In each case where the ends of the sections 6, 7, 8, and 9 come together, they overlap as indicated in Fig. .5, and extend through slots in the opposing flanges 5, 5, the overlapping ends of the sections 8 and 9 being designated by the numerals 10 and 11 in Fig. 2. The overlapping ends of the stiffening rin sections are provided with slots 12 (Fig. 1%, which slots 13 lying on oppositesides of the vertical es 5, 5. When the wedges 13, 13 are driven downward, they not only serve to apply tension to the sections 8 and 9 but also serve to press the opposing faces of the flanges 5, 5, tightly together. The flanges 5, 5, are still further secured together where necessary by means of slotted key members 14 extending through the flanges- 5, 5, and carrying the wedg s 15.

The construction as above described permits of the formation of columns of widely varying diameter, while still using the same segmental plates. For instance, the plates 1, 2, and 3 may be of a standard width, so that by adding or subtracting sections the diameter of the column may be varied by units, depending upon the width of the plates 1, 2, and 3.' For instance, if the width of each of the plates 1, 2, and 3 issuch that one late taken alone will form a column eight inches in diameter, then the three plates receive the wedfges an would form a column twenty four inches in diameter, and the addition or subtraction of another plate would vary this diameter by eight inches. The plate 4 is used where the variation desired is less than could be secured by omitting or adding a plate of the width of the plates 1, 2, and 3, and if desired, the Width of the plate 4 may be made such as to correspond to an increase in diameter of one, two, three, -or any desired number of inches. It will be seen that by using a fewstandard widths columns of any desired diameter may be secured.

The segmental plates 1, 2, 3, and 4 are of course made of relatively flexible sheet 'metal, and it is the function of the rigid stiffening members 6, 7, 8, and 9,,not only to add strength'to the molds, but also to make the mold conform to an approximately true circularcross section when the stiffening bands are applied. It will be seen that the wedges-13 when driven in position, serve to apply tension to the Various sections of the stiffening bands, so that when the wedges are driven tightly into place the flexible metal is forced to conform itself to the inner surface of the bands, and a mold of approximately true circular cross section is secured, even where the segmental plates 1, 2, 3, and 4: are forced a considerable distance from the. position of curvature which they would normally assume if entirely free. A set ofstiifening bands or bars is of course provided for each diameter of column, such bars being accurately formed to the desired radius, so that the mold when completed is of substantially true circular cross-section of the desired diameter. The number of sections into which these stiflening bands or bars may be divided may be varied to suit conditions, it beingdesirable, however, to make the numberpf parts as small as possible without interferin with the freedom of removability of suc parts. I have found it most convenient to use one section of band per eight inches diameter of column or fraction thereof, but other arrangements are possible.

In manufacturing the form, the segmental plates are first cut to the proper dimensions, next the slots are punched in the edges in proper position, the plates are then rolled to a given curvature, and the flanges are then bent back in an ordinary breaker. By this method of manufacture, using automatic machinery as far as practicable, the plates'will be exactly alike.

Where two lengths of tubular section are used together as indicated in Fig. 2, the distance pieces 16, of wood, may be employed if any unusual vertical strain is to be imposed upon the upper section, such as. that involved in supporting a superstruc-' ture of some kind. In the arrangement, illustrated the lower section telescopes inside of the upper section, and the distance pieces 16 are of such a length that the roper amount of overlapping is secured. t will be seen that the distance pieces 16 serve as a means of support of the upper bands or bars 8 serving as very effective bearing surfaces for the ends of the struts 16. Ordinarily the distance pieces will not be necessary, as the one section clamps the other securely at the interengaging telescoping ends, and a considerable weight may be imposed on the upper section without disturbing the relation of the sections.

It will be understood that the apparatus is not limited to constructions in which the mold or stiffening bars are strictly circular, and that the term circular is used in the specification and claims in its loose generic sense, to include devices having an approximately circular form such as might be formed by a somewhat flattened circle or other similar forms departing somewhat from true circles.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is the following:

1. A mold for forming upright concrete bodies circular in cross section, which comprises a plurality of segmental sections together forming a circular mold and each consisting of a flexible metal plate with perforated out-turned flanges at its vertical edges, a plurality of removable segmental stiffening bands encircling the exterior of the plurality of plates and extending through the said perforations in the flanges of the plates, and releasable means cooperating with both the bands and the flanges whereby the said flanges are pressed tightly together and the bands are held against circumf'erential or radial movement, the bands being sufliciently rigid to 'maintain their shape and make the flexible plates conform thereto.

2. A mold for forming upright concrete bodies circular in cross section, which comprises a plurality of segmental sections together forming a circular mold and each consisting of a flexible metal plate with perforated out-turned flanges at its vertical edges, a plurality of segmental rigid stiffening bands perforated and overlapping at their ends encircling the exterior of the plurality of plates and extending through the perforations in the flanges, and wedges extending through the perforations 1n the;

overlapping ends of the bands and engaging the said flanges.

3. A mold for forming upright concrete bodies circular in cross section, which comprises a plurality of segmental sections together forming a circular (mold and each consisting of a flexible metal plate with outturned flanges at its vertical edges, means for releasably clamping the said flanges together, and circumferential hoops detachably secured around the assembled plates and extending through the said flanges, the said hoops being of greater stiffness than the plates so that the curve of the hoops governs that of the plates.

4. A mold for forming upright concrete bodies circular in cross section, which comprises a plurality of segmental sections together forming a circular mold and each consisting of a flexible metal plate with outturned slotted flanges at its vertical edges, and a stiffening hoop of suflicient rigidity to maintain its shape and make the plates contormto such shape around the plates consisting of'a flat metal band set edgewise and made up of a plurality of sections with their ends overlapping and detachably secured together and extending through the said slots in the flanges.

5. A mold for forming upright concrete bodies circular in cross section, which comprises a plurality of segmental sections together forming a cylindrical mold and each consisting of a flexible metal plate with outturned slotted flanges at its vertical edges, a rigid detachable sectional band encircling the plates and extending through the slots in the said flanges, and means whereby tension is applied to the band to make the plates conform in contour to the band, the sections of the bands being relatively rigid and serving to hold the plates to the proper curve.

6. A mold for forming upright concrete bodies circular in cross section, which comprises a plurality of segmental sections together forming a cylindrical mold and each consisting of a flexible metal plate with outturned slotted flanges at its vertical edges, a detachable band of bent rigid sections encircling the plates and extending through the slots in the said flanges, and means whereby tension may be applied independently to the sections of the band.

7. A mold for forming upright concrete bodies circular in cross section, which comprises a plurality of segmental sections together forming a circular mold and each consisting of a flexible metal plate, a band adjustable as to length and comprising a bodies circular in cross section, which comprises a pair of contractible tubular sections placed in telescopic relation, one above the other, a stifl'ening band around each section and removable distance pieces between the said bands.

9. A mold for forming upright concrete bodies circular in cross section, which comprises a pair of contractible tubular sections placed in telescopic relation, one above the other, a contractible sectional stiffening band around each section, and removable distance pieces between the said bands.

10. A mold for forming upright concrete bodies circular in cross section, which comprises a pair of tubular sections placed in telescopic relation one above the other and each consisting of a plurality of segmental flexible plates with out-turned flanges at their vertical edges, a sectionalstiflening band around each section extending through the flanges of the said plates, and distance pieces between the said bands.

11. A mold for forming concrete bodies, comprising a shell having opposing outturned perforated flanges, a band extending around the shell and having its ends perforated, overlapping, and extending through the perforations in the flan es, and wedges extending through the 'pertorations in the overlapping ends of the bands and engaging the said flanges.

In testimony whereof I have hereunto signed my name in the presence of the two subscribed witnesses.

WILLIAM M. VENABLE.

- Witnesses:

LETITIA A. MYERS, ARCI-IWORTH MARTIN- 

